In the paper sheet handling industry many devices are known for jogging individual sheets into stacks of sheets. One such jogging apparatus is disclosed in co-owned and copending U.S. Patent Application Ser. No. 144,539 entitled Paper Sheet Stacking and Jogging Apparatus. In that apparatus, a jogging motor is connected through appropriate gearing to simultaneously impart motion to two orthogonally oriented jogging fingers. These fingers are offset from one another so that a jogging motion is imparted to a sheet against a paper stop in one direction followed immediately by a jogging of the same sheet against an orthogonally oriented paper stop in a second direction by the second finger. In this apparatus, offset job stacks are created by varying the positioning of various sheet stopping surfaces.
Other jogging devices are also known which employ rotating fingers, rotating brushes, vibrating plates, multiple fingered paddle wheels, multiple strips, or belts.
With the exception of the above referenced co-owned apparatus, none of the known jogging devices are particularly effective for use in jogging individual sheets fed from a modern high speed printing or copying device into precisely aligned offset job stacks. Moreover these other jogging devices operate continuously and tend to cause damage to the quality of the printed paper surface and the printing thereon. Finally, these devices tend to be insensitive to the necessity for imparting the jogging motion to the top most recently fed sheet without imparting significant movement forces to sheets next below. Where jogging devices impart movement forces not only to the top most sheet but also to the sheets next below, uneven stacking is the inevitable result.
With respect to the above referenced co-owned invention, which does indeed produce sharply defined offset job stacks from individually fed sheets delivered at high rates of speed, a related orthogonal sheet stop mechanism having movable and repositional first and second sheet stop pairs must be employed to effect the offset stacking. The jogging device above referenced cannot create offset job stacks where there are only stationary sheet stops.
There is therefore a need for a jogging apparatus in the paper sheet handling industry which can jog individual sheets fed from high speed printing or copying devices into precisely defined offset job stacks, and do so without damaging the paper surface or print quality of the sheets. Typically this will require that the jogging mechanism is capable of intermittent, as opposed to continuous, operation. There is also a need for a jogging apparatus which will impart motion of any significant force only to the top most sheet, or the most recently fed sheet, of a job stack. This device should be capable of reversing the direction of its jogging motion to jog sheets selectively against a side sheet stop and backstop, on the one hand, or, alternatively, against a second side stop and the same backstop.